i have older SmartUPSes from APC (SU1400RMI2U) which either put out a better sine or have a faster transfer time because the PSUs in the DL380 acts very natural when they switch over to battery.

Aren't all SmartUPSes supposed to put out a clean sine?

I'm going to bring my Tektronix from home and check just how much of a sine is the SC1500's output really, but i was just wondering if this is a common problem with the SC1500 or i've been delivered some duds.